The invention relates to a process for collecting false-twist heat-set yarn having a denier between 10 and 100 on a pirn under controlled tension. More particularly, it relates to such a process wherein the yarn properties are modified so as to give better knitting performance and superior quality in fabrics knitted from the yarn.
Yarns textured by the false-twist heat-set technique are referred to herein as "crimped yarns" for the sake of simplicity. Crimped yarns are customarily collected immediately following the texturing operation either on packages using a ring-and-traveller takeup mechanism which imparts twist to the yarn, such packages being referred to herein as pirns, or on bobbins without twist using a conventional winding mechanism to form "cheese" packages. The wound bobbin or cheese packages frequently cannot be used for directly feeding a knitting machine, necessitating repackaging the yarn onto cones prior to knitting. Pirn packages have different package formations and are more suitable for directly feeding a knitting machine due to lower and more uniform tension as the yarn is withdrawn over-end by the knitting machine.
However, hosiery knitted from pirn packages heretofore have frequently suffered from visible vertical streaks, the streaks being more severe and objectionable when using heavy denier yarn than lighter denier yarn. It has been discovered that the streak problem can be substantially reduced or entirely eliminated by operating the ring-and-traveller takeup mechanism in a particular manner.
A primary object of the invention is to provide a pirn package of crimped yarn having properties such that hosiery knit from the crimped yarn exhibit little or no visible vertical streaks.
A further object is to provide a process for making a pirn package of the above character.